Ahhh, another audio junkie. I splashed out on a Blue Yeti a while ago, definitely worth it for clarity compared to the awful integrated mics.

A trick I remembered a while ago about reducing desk noise without a shock-mount is to use an old speaker cone. You put the mic on a stand of some kind (or your tripod in this case), then put that on top of the cone. When you bang the desk, a lot of the vibration will be absorbed.

When you get a boom arm to mount the mic, that will absorb some of the desk vibration too, but if you move it around, those vibrations will be picked up. You can reduce this rumble effect by using a highpass filter, 40-120Hz range at 6dB per octave or so.

You can get by without a pop shield if you don't speak directly into the mic, but instead, just above or across it. Cardioid patterns should still pick you up just fine without too much gain adjust.

If you plan to do voice-over stuff instead of live, you can cheat a bit by covering your head and mic with some bedding, that'll cancel out a lot of background noise and reverb- but this can leave you with what's called a 'dead' sound. If you plan to do live stuff, then there are really only two things to do. Stick some bedding behind you on the wall or something, and put a pillow or small cushion behind the mic to cancel off-axis reflections. You'll still get some ambient reverb, but this will keep some of the natural acoustics.